Display Left Menu

This will show a list of the pages (Branch Tables) in the lesson.

Also, by specifying a grade greater than 0, the user taking the Lesson must have a grade equal to
or greater than the grade set in order to view the Left Menu. This allows Lesson designers to
force users to go through the entire lesson during the user's first attempt. Then, if a user
retakes the Lesson after meeting the required grade, s/he can see the Left Menu to help with review.